ok guys ive already researched this on this forum and i was not satisfied w/ the answers. i have an 87 LG4 LT camaro i want more hp and tq. specifically i want 400hp and about 415 tq. i need to know which engine is the best price, most dependable, and easiest on gas. i have a 4 bolt main 350 block so i just need to know which is better. thanks in advance.

 

Best price.

Dependable.

Easy on gas.

You can have two of the three. Which do you really want?

 

If you've never built an engine over 300 HP before, stick with the 350.

 

yea..i am wondering the same too..but i have a 305 rs..and wondering which engine would be better to drop in??? i am looking for dependable engine with high horse power potential..also looking for cheapest price and i don't really care about gas...if u can squeeze my qtn in..that would be sweet..thanks

 

When it comes to High Horses, reliability and cost are not totally on the same radar screen. Oh, reliability can be done, but it costs if you want to be able to drive it home on a winter's night.

Something drivable is also more enjoyable than having the 400 horses with it crying and complaining up to 2,000 rpm before it's happy.

IMHO, go with a 400 small block, and built it for 5500 RPM or less. Torque is where it's at if you "street race." I think that's the term used by the supr2nrs (they can't even spell properly )

HP is a function of TQ, remember that, and there's no substitute for cubic inches. Suck it up and save the money and get a good big-inch engine, and you'll be more than satisfied.

 

I've got to agree here. The more cubes an engine has, the less you have to push it to make more power.


I can't find the exact dyno #'s, but a few years ago I built what I thought was going to be a really mild 400....it turned out to be a stump puller.

- GM 400 block - bored .030 over -
- Stock 400 crank turned .010 / .010 and polished
- Cast pistons @ 9.8:1 compression ratio
- Cam was a Lunati grind, but really mild, really close in specs to the Comp Cams 268
- 487 casting # GM heads...not the greatest performance head, but not the worse, and I had 'em...I had these cleaned up, steam holes drilled, 3 angle valve job done, new springs etc.
- With 1 5/8" headers, a Q-Jet, and a Performer RPM intake it made @365HP @ 5400 RPM and over 440 ft/lbs of torque at @ 3800 RPM.

And I still consider this a VERY mild 400. I kept the stock 400 short rods, and just had 'em checked to see if they needed resized, and used new ARP bolts.

Like I said this was MILD. No lope at idle, never ran hot, got decent gas mileage w/ low 3.xx gears and an OD tranny.

No 1/4 ET's as this motor was in a full size 4WD.


Best bang for the buck, for a primarily street, some strip, SBC is the 400 and a set of Vortec heads and a good cam.

I've seen plenty of guys go this route and retain enough street manners to drive everyday and still knock down VERY respectable ET's at the track on the weekends.


A 383 can do just as well with the right setup, but can get more expensive, depending on how much the 400 core costs to begin with.


You can ALWAYS add more cam etc...but an engine built to make high HP usually ends up a turd on the street unless you add a big stall, and steep gears....

It's all about compromise....


About the best advice I've ever heard regarding building a good street / strip SBC was this...

"Get the BEST set of heads you can afford...even if it takes you longer to put it together....you'll NEVER be sorry..."


HTH

Just my 2 cents

 

You could build a 350 with Vortec heads, Perfromer intake, and the Hotcam kit and be pushing 400 horses. They had an article about this build in CHP a few months ago. Personally, I'm going with the 400 sbc.

 

He wouldn't want to get a 400 if he already has a 350 4 bolt main block... For what you want, I'd say go for a 355...

 

Yes, I stand corrected as he already had a 350 4 bolt. well, if it's in good shape, it could bring enough dough to get a 400 block.

There's still no substitute for cubic inches. 383 is the way to go but will cost a considerable amount more than a 350. Heads and cam make or break how happy you will be with a motor. The other serious consideration to keep is whether or not you'll stay with the fuel injection or go carb/mechanical distributor, as this will affect your cam decision.

Perhaps you could tell us your goals on what you'd like car to do... Light-to-light? Freeway (or interstate as we right coasters have)? Back Roads corner carver? Strip? Leadfoot? Lightfoot? Gearing? Manual/Auto? Headders? Fuel Economy? Budget?

We're here to help!! Just tell us your goals and we'll do the best we can to help out!!

 

You have what alot of grown men want. A 350 with four bolt mains. The 383 in that housing will give you big block torque numbers and small block reliability. If you you stay with a reasonable carb i.e. under a 750 double squirter you can also have daily driveability,not to mention more foot pounds of tork than 99% of people next to you at the stoplight. Be a BIG BOY and stroke it

 

383 :hail:
This is my vote. I went back and forth on the teeter-totter for quite some time before choosing a 383. If you plan to get all things new then a 383 isn't too much more $. Plenty of places have rotating assemblies you can pick up and all the other parts necessary. This will be dependable, slightly more than a 350, but hey if you plan to replace all internals anyways. The only thing that you might loose a little on is gas. But just because its a 383 doesn't mean that your compression ratio will be through the roof and you can easily stay on pump gas.

 

87trans not just punp gas but premium pump gas. Alot of people forget that cheap gas can cause detonation. So stick with the most expensive petro available and dont use the worthless octane booster to obtain higher octain numbers

 

well, ok...heres the deal. im a senior in highschool and im going to college 2 hours away from my house next year. so sometimes this car will be on the highway for me to come home. i have like 2 grand saved up. i cant seem to get anyone to say a 350 is what you need or a 383 is what you need. everyone says something different. my goal is 400hp and 415tq with out nos. i have a good machine shop over here now i just need to decide which engine 383 or 355 and what kind of stuff to use. your info so far is good. please keep it coming.

 

MAYBE I DIDNT SAY IT LOUD ENOUGH 'STROKE IT' LIKE A MAAAAN

 

I'd go with a 383 like the man said. I built one for around 2,000 that made similiar numbers you are looking for. I got a great deal on the heads, block, and crank though. Remember, you're looking at a lot of additional machine work. A 383 is NOT as reliable as a 350. Anytime you put something where it shouldn't be (i.e. the crank), there is a greater potential for problems. I'm not saying this significantly increases the risk of the engine grenading, but it does increase the risk. It will be easier to make 400hp with more cubes. The 383 making 400hp will be more streetable than a 350 making 400hp. Good luck in your decision.

 

ok well, what is the price difference and gas mileage difference in a 383 and 350? im leanin more towards a 383 cuz it sounds like its gonna be more dependable and less stress on the motor. but this is probably still gonna be my daily driver so gas and dependability are a factor. i have a good machine shop over here and a friend of mine says he can get me good prices from them.....cuz he knows the owner. thanks in advance for your input.

 

As a college student meself, here's what I'd do in your position. I'm asuming you have a 305 in it right now. I'd go 350 then. You won't get 400 HP and 415 TQ, but you'll have a good solid and reliable motor in the 350 that shouldn't cause you overheating, etc.

Anything over 350 is too much for the stock cooling system, and you'll constantly overheat, which will shorten the life of ANY motor. More cubes =more power but it also = more heat.

Find out what rear gear you have. A 350, with 600 CFM carb, intake, good heads, mild cam, headders and cat back, with 3.23 rear gears will be plenty potent and reliable with decent mileage. It's probably around 350 HP and close to 400 TQ. done right for $2000. I'd guess somewhere in the neighborhood of 16-20 MPG on a 700R4 automatic, weather and style dependant.

Get a PAW performance catalog, it's the best $5.95 I ever spent. Not only do they give good pries on parts, they have tech articles explaining what to look for and differences between parts in a fairly non-biased manner. They sell individual parts on up to complete stroker motors.http://www.pawinc.com/

Just my 2 cents worth.

 

thanks for all your input guys. i talked to some more people around here that race and ive decided to build a 355. it will be more streetable and im gonna get 400 horses out of it. i will build a 383....just not right now. after college i definately will. anyway thanks for all your help in making my decision.

 

I agree with the decision on the 355. One of the best purchases I ever made was to buy a book by John Lingenfelter (Drag Racer/professional engine builder), about maximizing street potential for a SBC. The book agrees with the common consensus here that torque is the factor that kicks you in the *** when you press the pedal. The book is very helpful in matching parts such as heads, cams, intakes, and locating the better stock casting numbers. Example: the 350 that I'm building has #882 heads on it which are boat anchors. The book sent me in the proper direction to find a set of #487x heads, and while these certainly aren't performance masters, they are some of the better stock ones out there and won't set you back too much.

I'm building my engine as follows:

1. Balanced engine kit from P.A.W. (they're right, they have it all) .040 over, flat-top forged pistons.

2. Edelbrock Performer RPM Dual-plane intake

3. Edelbrock Performer 750 cfm carb (with electric choke kit)

4. Moroso Oil Control Kit, with windage tray, crank scraper, baffle (to keep the rotating assembly spinning as freely as possible)

5. Shorty Headers w/high flow cat and Borla Exhaust

6. B&M shift Improver kit (700R4)

7. Specific cam undecided as yet, but somewhere in the range of 220* duration @ .050, and about 475 lift (pretty mild)

8. HEI Ignition w/hotter coil

9. Roller rockers

According to what I've read, this should make somewhere in the neighborhood of 350-375 HP and 400 tq. Plenty of fun to play with and still dependable enough to drive every day without big headaches. BTW haven't checked my rear housing yet, but I've been told my car has 3.23 gears.

I'm sure somebody on here will tell me this combo is crap, but from the research I've done it matches up pretty well.

Just my opinion.........

 

Yea, the 355 is a better idea than a 383 for a budget build.

 

if im tryin to get around 400hp out of the 355...how much do you guys think ill end up spending? i know you cant give exact prices. but i was just wanting estimates or maybe from past experiences. thanks
-Ryan-

 

383 with a tpi ported or edelbrock ,accel stuff.
You will have to get good heads like afr or brodix.
then you can have 400hp and 500ft. lb. and be very happy
GM just made a 383 short block available that would be a great start to a great motor, just add heads, your intake and ign.

 

Ok, here's what you'll need (according to Desktop Dyno)

355 (350CID with .030 overbore)

Wedge/Pocket Porting Heads/Large Valves
-Look for DartII Or Sportsman II heads to fill this application.
Int. 2.02" Exh. 1.60"

Compression Ratio of 9.5:1

a 750 CFM carb

Good Dual Plane intake manifold

Small Tube Headders/Muflers

High Performance street roller cam
.465/.441 lobe center of 108*

31 degrees of initial timing.

Total output is 424 ft/lb of TQ @ 4500RPM and 421HP @ 6500RPM
The TQ band never drops below 364 from 2000-6000RPM, which will make for a nice street machine.

I would definitly opt for stonger rods as well. If you have a fuel inj. and an auto (which I suspect you do) You'll have to do some cam research to find what will work under those applications.

FWIW a 383 with the same setup is 422HP @ 6000, but offers 446 ft/lb of TQ at 4500 RPM, with 400+ ft.lb frm 2000-5500 RPM.

If all you want to talk is HP, those 30-odd inches only gain you 1 HP at a lower peak RPM.

 

Contact summit and jegs for their free catalogs. Then send the 5.95 for a PAW catalog. The thing is huge!! Then take the above list and build a spreadsheet.

Include a rebuild kit if you need it (pistons, pins, rings, bearings, etc.) and at the very least a set of reconditioned rods.

Check for local swap meets as well as eBay etc. for used heads intakes, etc. to help cut your costs.

It'll take some time, but you can build this motor for about $1,000... perhaps even less!!

 

man this board if awesome. ive learned so much. the 350 4 bolt block im getting is an early 70s model. how is that gonna effect my swap? will the cranks be different or is it just the rear main seal that is different? thanks in advance.
-Ryan-

 

i think there has been a few things on the 383 choice left out here.

1st, clearence probs...... cam, and block will need to be handeld appropriatly, small base circle cam will be a must if not even stroker rods that run 400 or more..... and block grinding that will cost 100 at a reputable machine shop.........

2nd, more cubic inhes means more airflow will be needed to make any good power......

consider atlest vortechs, and if ya can canfield or afrs.........

 

As good as it sounds Desktop Dyno isn't always right....Plus that just power from the motor, not to the ground...Desktop Dyno told me if I put headers on my stock 82 LG4 305, I would have 265 hp...ha ha, good one!

 

It's a ballpark figure. They assume a dual exhaust setup, I think full-length headders, standard rocker arms, and it fudges items in the cam and head flow. A simple rise or drop in Barometric pressure can affect horsepower readings.

I'm aware of it being not accurate, but it's as close as you can get, and provides for interestnig bench racing arguments
I'm more interested in torque output than Horsepower, since all of my driving is 5500 or below, so I look to see which cams give the best TQ curve, rather than peak HP, because HP is a function of TQ. Just my view of the world, that's all.

 

Don't get me wrong, I love my Desktop Dyno, I am very very happy with it, I am jus saying when your dealing with stock motors it seems to over esitmate, When your actually building a somewhat powerful motor and know what you want, Its usually right on Target. I use it bfore almost upgrade I get for my 327 I'm building!

 

Everything should bolt onto your early 70's block no sweat. Your 87 heads are different than '86 on back heads, but they should bolt onto the block without any problems. If you decide to go the roller cam route with this block, you will need retro-fit roller lifters, which are not cheap, but roller cams seem to be worth every bit of their weight in gold.

Vortec heads seem to be the "cheap" way to go, although I've read they need machine work for screw in studs, and come with smaller valves as well. The other issue is your intake/fuel setup. Do you have a carb, or fuel injection? Will the 87-up stuff bolt on? I don't know too much about the later motors. try www.gmpartsdirect.com and search for vortec.

Don't quote me on this either, but you may need an '85-back flexplate or flywheel. If you do, I've got like 4 of em here in the garage that I can send you. As long as your flywheel/flexplate is from a 350 or smaller SBC, you'll be fine.

 

You can get modified Vortec heads from Scoggin-Dickey for $320 each. These heads have new (bigger) valvesprings and the valvestems have been cut down to accept higher lift. With those modifications you can run up to .525" lift, or I think Pace Perf. sells some for up to .550" lift and they come with screw in studs, although they are $380 each. The heads come with 1.94"/1.50" valves which are small, but it's not really worth the money to install bigger valves in them, you wouldn't see a big increase going with 2.02/1.60 valves. If you do end up going with Vortecs (I would reccomend it, I am) then you will also need a Vortec style intake manifold which is about $160, however I'm not sure if they make a TPI intake base for Vortecs.

 

well, my lg4 is carbed right now and i plan on staying carbed......im also gonna run nitrous if i build this motor. thanks for the good info. keep it comin guys.

 

Well I hope you're going to get rid of that QuadraJet and replace it with a real carb. I'd go with a Holley 750cfm 4160 for auto, or if you're running a manual I'd go with the double pumper 4150 model. You will also need to get a new distributor since the old computer controlled one will not work with a mechanical carb. I would reccomend finding a good core at a junkyard for about $20 and then get the Proform rebuild kit for $80 at Summit. That's the cheap way, but if you've got money to burn you can buy a new Proform distributor for $130. The Proform rebuild kit comes with all the components used in the Proform dizzys, and it replaces everything (except the core). It comes with 50k volt coil, cap, rotor, module, vac. advance canister, etc. Summit doesn't have it on it's web site, but it's in their catalog. I'll get you the part number when I get home.

 

Replacing the q-jet is an excellent way to spend money that won't increase power.

 

I have so many problems with my quadra-jet, I cant wait for the day when my new motor comes in and I junk it. My car is not going to be computer controlled once I get finished with my 327 and get it installed this June.. Holley's are simpler and easier to tune, if you know what your doing....

 

Unless it's a modified q-jet a holley will make quite a bit more power.

The PN for the rebuild kit mentioned above is: PRO-66945 RC

 

For around $1300 you can get a Holley kit that has the heads, cam, and intake manifold that will put out 425 horsepower. If that helps.

 

so the 350 4 bolt i had is an early 70s model. that means that none of my accessories will bolt up. cuz mine is an 87 and a serpentine system. so my a/c and all that crap wont work now if i swap it. ive looked for a long time for a good block. how much more would it be if i bought new accessories? its very hard to get a hold of a good 350 block....everybody uses them and nobody will sell one.

 

Having you accessories fit has nothing to do with the block. It all depends on the heads and whether they have accessory holes (if any) and where/how many there are. If you are using the stock heads, it will all bolt up. I believe the Vortecs will have all necessary bolt holes also. Some early model heads however do not come with access. bolt holes and they would have to be drilled and tapped into the head. Most late model heads do have access. holes though, so as long as you get some newer heads you'll be fine.

 

ok well, me and my mechanic have been arguing about whether i can use the 70s block or not. but according to what you guys are saying as long as i get the right heads i can use all my accessories and a/c and all that correct? thanks so much you guys are freakin awesome!!!!

 

Yes, that is correct. However if you do use headers (which is reccommended) you might have to modify the A/C bracket. I'm not sure if you have to, but I did on my 85 Z28. It's not hard though, nothing a hacksaw can't take care of, all you have to do is cut a notch out of it where the # 1 header tube will be.

 

Until I started using slicks, the best 1/4 mile MPH I had was with the q-jet (Edelbrock 1901). I've done so many other things since then, but the improvements I had with the Holley did not relate to power.

(FWIW, the main problem I had with the Edlebrock q-jet was the AV motion was not smooth - so, opening was inconsistent, and neither were my ET's. I never had that problem with factory q-jets.)

 

Vortec heads will work. Most heads (except racing heads) have what is called a "universal pattern" drilled and tapped for accessory holes. Just make sure the heads you go for have a "universal" application.

 

Whatfor junk yard do you go to??? The 4 yards around here are all FWD GM A-X bodies and Chrysler K-car borthers and sisters with their 2.2L slant 6 derived cousins. The last time I saw a 4bbl in the yard it was a Q jet. A CC-Q-Jet for a 3rd gen F-Body!! Let me know where this yard is so that I may take my holy pilgramage to this mecca of holy junked automobiles!!!

I went to 2 yards looking for a hood and front bumper for my 86 bird and I saw a total of 4 third gen firebirds. These are multi-acre lots that claim to be the "worlds largest." Harry's U-Pull-It
I'd love to get a 'glass hood, but $$ prohibit such a luxury right now. I'm looking to do a T/A conversion as I think they look nicer than the std birds.

 

Actually I bought mine from somebody on this site. 2 for $40, one was a core and the other only needed cap and rotor. I haven't looked at any of the yards around here, but I know I could find a core for $20 if not less.

 

Hey 86Bird. I see your from Danielsville, I live in Bushkill township. We're almost neighbors. You ever been to Fatzingers in Bangor? He used to specialize in third gens. He's sort of going away from them to Hondas and other imports. He used to let you on your own too. I got alot of parts for my TA there. I've heard he don't let you crawl around as much as he used to. He should still have a lot of parts, and his prices are really good.

 

I live on the border of Lehigh and Moore. I've been to the Harry's and Joes in New Ringgold, though Joes has been closed for a while... Yeah, we practically are neighbors! I have heard of it, but haven't been there before. I've also heard of a place called Deerfoot near Wind Gap. E-mail me if you know of anyone who had a T/A front clip otherwise.

 

ok i now have the 350 4 bolt main block....now i need suggestions on parts to make this thing 400hp. im gonna bore it to a 355 and probably use 100-150 shot of nitrous. so please tell me what you would use on this engine. everything from carb to oil pan. thanks a lot in advance.

 

I thought you decided to go 355 for economy and reliability going to and from college. Now your back to 400 hp and a 100- 150 shot of NOS. Who are you trying to fool me or your wallet? I still say be a man and build your dream not the little kid next doors dream.

 

Modified Vortec heads, Comp Cams XE268 cam (or 274 if you want a real screamer), Performer RPM intake manifold and a good 750 cfm carb. That's 400 horsies right there.